Lead wire threading machine



Dec. 4, 1945. J V ELL. 2,390,139

LEAD WIRE THREADING MACHINE Filed June 27, 1942 2 Sheets-Sheet 1 9INVENTOR.

Anthony J Vasselh;

Dec. 4, 1945. A J VASSELU 2,390,139

LEAD WIRE THREADING MACHINE Fiiea June 27, 1942 2 Sheets-Sheet 2 INVETOR.

Anfhorzy d. assellb.

ATT E] R NEYI Patented Dec. 4, 1945 LEAD WIRE THREADING MACHINE AnthonyJ. Vasselli, Newark, N. J., assignor to Radio Corporation of America, acorporation of Delaware Application June 27, 1942, Serial No. 448,742

14 Claims.

My invention relates to machines for threading or guiding lead-inconductors. or wires of the envelope of radio tubes and the. like intohollow contact pins on the base of the envelope.

The final operation in the manufacture of many electrical devices havinga number of lead-in conductors connected to contact pins on a baseelement,'such as radio tubes, comprises threading the conductors intoand through the center of the tubular contact pins, and soldering theouter ends of the pins and conductors. Because the conductors areusually long, slender and quite springy, it has heretofore not beenfeasible to thread the conductors into the pins by machine, andthreading has been performed by hand. In hand threading, one lead at atime is straightened and guided into its pin.

An object of my invention is a machinev that will guide lead-in wiresinto contact pins on the base of the envelope of radio tubes and thelike.

Another object of my invention is an improved method of threadinglead-in wires into contact plIlS.

The characteristic features of my invention are defined in the appended.claims and one embodiment thereof is described. in the followingspecification and shown in the accompany drawings in which Figure 1 is aplan view, partly in section, of my improved base threading machine,

Figure 2 is a sectional view of my machine taken along line 2-2 ofFigure 1,

Figures 3, 4, 5, 7 and 9 are end views of an envelope and showessential, successive steps in the threading of a base on my improvedmachine.

Figures 6 and 8 are side views, respectively, of Figures and 7,

Figure 10 is a cross sectional view of the tube guiding means and istaken along line Ill-I0 of Figure 2, and

Figure 11 is a schematic view of the wire straightening means of myinvention.

The particular envelope l and base 2 chosen for illustrating my improvedbase threading machine and its.operation, is for the so-called' allmetaltube and comprises an insulating wafer or disc carrying a number ofparallel hollow contact pins 3, preferably arranged in a circle. Theenvelope is cylindrical and the lead-in conductors or wires 4 passthrough a glass header 5. in one end of the envelope. The points atwhich the wires enter the header preferably lie in a circle, which inthe particular tube illustrated is concentric with and slightly smallerin diameter than the circle in which the contact pins are arranged. Itis a comparatively simple operation to pull kinks out of the wires andcut them to a uniform length, but because of the length and slendernessof the wires they cannot be made to stand perpendicular to the header,and the outer ends of the wires will move to random positions. Automaticmachines have not as yet been devised for finding the ends of the wiresand guiding them into the small openings in the contact pins. The onlypoint on the lead, which is predetermined and which can be "found is atthe base of the wire where it is molded into the header. According to myinvention each of the wires is first engaged near its base by a hook'li.Each hook is carried on radially slidable fingers 1, and is movedoutwardly to give the wires a set at an angle approximately 30 with theaxis of the tube, so that when the finger is then moved inwardly it mustwork against the natural springiness caused by the set in the wire. Acrotch or V slot 8 is made in the finger opposite the hook 6. After thewires are given an outward set, the tube is moved lengthwise, away fromthe fingers, to bring the fingers near the ends of the wire, whereuponthe fingers are moved radially inward to bring the crotch 8. exactly tothe base pin circle on which the contact pins are arranged. Wires lyingin the crotches, hence, are effectively held on the pin circle, and bysimple rotational orientation of the base over the ends of the wires.the wires can all be shoved simultaneously into the pins.

The guide for moving the envelope along the center line of the envelopeand perpendicular to the base preferably comprises a bracket 9 attachedto the bottom of the frame of the machine and having V ways. l0extending perpendicular to the plane of the fingers. A step II in theways accommodates the large flange at the end of the envelope andvconveniently serves as a lower stop for the envelope to measure thelength of the wires and insure engagement of the fingers with the endsofthe wires.

The successive. positions of one of the fingers with its crotch and hookare shown respectively inv Figures 3 to 9, inclusive. The envelope, withthe wires standing in random positions about the exhaust tube, is placedagainst its guide and moved to the upper or dotted line position shownin Figures 2 and 3. The fingers are then moved inwardly and the tuberotated slightly to engage the lower ends of the wires with the fingersas shown in Figure 4. The fingers then move outwardly as shown inFigures 5 and 6 to bend the wire through a sufficiently large angle toworkharden and set the wire. Soft or annealed held in a circle equal indiameter to the diameter of the base pin circle. Shoulders 12 on thefingers in this position are, as shown in broken lines in Figure 2, somade as to guide the base over the envelope and center the contact pincircle over the circle of the ends of the wires. The base may be rotatedslightly to bring the pins and wires into alignment or registry, theparticular rotational position of the base being determined visuallywith index marks or mechanically by notches and the like. While the baseis held down the tube is pushed up and lead wires enter and pass throughthe base pin holes. A slight outward movement of the fingers accompaniedby a slight turn of the envelope disengages the hooks from the leadwires so that the fingers may be retracted and the threaded tube andbase re-- moved.

The fingers I preferably travel on a line extending through the centerline of the envelope, but could. if desired. be made to move along linestan ential to the pincircle or to a circle larger or smal er than thepin ircle. As shown in Figure 1, the fingers are radia ly slidable ingrooves in a metal annulus l3. The fin ers are biased inwardly by sprins M and their movement is conveniently controlled in unison by a cam rinl5 having inclined cam s ots l6 enga ing pins I! on the fin ers. As thecam ring rotates the pins move inwardly or outwardly in synchronism. Thecam slots may, if desired, have a step [8 upon which the pin I! may restto position the fingers in the wire threading position-of Figure 6. Thecam ring is biased in one direction by a spring l9 attached at one endto a bracket on the annulus I3 and attached at its other end by a screwto the cam ring. The bias is preferably applied to normally ho d thefingers in their outermost position as shown in Figure 1. A foot treadlemay be connected to the cam ring through a pull chain 2i to rotate thecam ring and move the fingers inwardly.

The envelo e usual y arrives at the base threading stage with leadsbadly twisted, matted,

kinked and bent, and before threading can begin I the leads must bestraightened and cut to the proper length. Various mechanical fingersand combs for untangling and straightening the wires have beenunsuccessfully tried.

I propose, according to another feature of my invention, to slidablygrip the ends of the wires between the toothed drums of a wringer andpull them straight. While the wires are tautened they all may be cut tolength by shears. As shown in the Figure 11 the leads are passed throughthe Opening 29 in the face plate 2|, between the cutting blades 22 and23 and into the rounded teeth 24 on the two drums 25 and 26. The teethare widely spaced and the circle of rotation of the teeth overlap onlyenough to slidably grip the wires between the points of the teeth. Asthe teeth pull the wires the envelope is drawn against the face platewith considerable force and moves the plate against the stop 21. Thedrums are geared together at their ends so that the teeth of the twodrums run in spaced relation, and one of the drums is eccentricallyjournalled so that it may be moved toward or away from the other drum.The spacing between the teeth of the two drums is easily adjusted withrelation to the thickness and stifiness of the wires, so that the wireswill be pulled straight without breaking. When the drums are driven at aspeed of-say 350 R. P. M., the wires inserted through the face plate arecaught by the teeth and straightened almost instantaneously. The cut-offshears for the wires may be manually operated or may be automaticallyactuated as by the magnet 28. The magnet winding is energized from thesource 29 connected by a switch 30 which is closed by the face plate.The operator picks up an envelope with say her left hand, bunches thewires so they will pass through the face plate hole and into the drums.The wires are straightened and cut off, whereupon the envelope with thestraightened wires is placed against the guide I0 and threading of thebase proceeds as explained above.

Good results have been obtained in threading the lead wires into thebase pins of so-called all-metal radio tubes of which the typescommercially known as the 6K7 or the 6J7 are common. These tubes have anenvelope about one inch in diameter and have eight copper leads about.015 inch in diameter andtwo inches long extending from the header ofthe tube. An operator can consistently thread the bases of 450 to 500tubes per hour with my base threading machine, whereas the same operatorcan thread no more than 300 per hour by hand. My improved base threadingmachine is inexpensive to make and is easy to operate.

The feature disclosed in. this application of straightening the wires bypulling them by means of toothed drums is claimed in an application inthe name of Anthony J. Vasselli, entitled Lead. wire straighteningmachine, Serial No. 612,163, filed August 23, 1945, as acontinuation-in-part of this application.

I claim:

. l. The method of threading a plurality of lead wires of an envelopeinto hollow contact pins circularly arranged on a base of the envelope,comprising straightening the lead wires, hooking each wire near its endadjacent the envelope and bending the wires radially outward at an angleto the plane of the envelope from which the wires emerge, then pushingthe wires adjacent their outer ends int a position in registry with thehollow contact pins and finally moving said envelope and base togetherto pass the wires into the pins.

2. The method of threading a plurality of lead-in wires of an envelopeinto hollow contact pins arranged on a base for the envelope, comprisingstretching the wires to straighten the wires, hooking simultaneouslyeach wire adjacent the envelope and bending each wire adjacent theenvelope, then reverse bending each wire by pushing its outerend into aposition in registry with the opening of its contact pin, and pushingthe wires into the pins.

3. The method of threading a plurality of lead-in wires of an envelopeinto hollow contact pins arranged on a base for the envelope, comprisingguiding the envelope along a line parallel to the center line of theenvelope and parallel to the. holes in the pins to be threaded, engagingeach wire near the envelope and bending the wire outwardly at an angleto the center line of the envelope, said bend being sufficient toworkaaoonaa Q push the wires into the pins.

4; A machine for threading a plurality'oileadin wires of an envelopeinto hollow contact pins on a base for the envelope comprising anannulus, a plurality of radially slidable fingers in said annulus, meansfor simultaneously moving all of said fingers radially, a blade at theinner ends of each finger, each blade having a hook and an opposedcrotch, and a guide-for holding said envelope n a line normal tothe'pl'ane'of said blades.

5, The method of threading into a pluralitycf definitely spacedapertures in a base a plurality of lead wires of an electrical devicehaving an end member from which the lead wires project in definitespaced relation different from the spacing of the apertures in the basewhich comprises bending the lead wires near the end member to workharden and set the lead wires with their ends spaced differently thanthe spacing of the apertures of the base, bending the set wires back topositions where the spaced relation of the outer ends of the lead wirescorresponds to the spaced relation of the apertures in the base, andmoving the base and the electrical device relatively to each other toinsert the lead wires in the a ertures of the base.

6. The method of threading a plurality of lead wires of an electricaldevice having a fiat end member with lead wires projecting alongside anaxis perpendicular to said end member through a base having a fiatportion with a plurality of apertures in spaced relation which comprisesengaging the lead wires near the end member and bending them away fromsaid axis intopositions wherev the spacing of the ends of the leads isgreater than the spacing of the apertures in the base, engaging the leadwires at points more remote from said end member and pushing them backto positions where the spaced relation of the outer ends of the leadwires corresponds to the spaced relation of the apertures in the base,and moving the base and the electrical device toward each other toinsert each lead wire in a corresponding aperture of the base.

7. The method of threading into parallel hollow contact pins arranged ina circle on a base, a plurality of lead wires of an electrical devicehaving an end member in which the lead wires are arranged in a smallercircle and projectin from said end member which comprises bending thelead wires outwardly from the center of said smaller circle and near theend member sufficiently to work harden and set the lead wires,positioning the outer ends of the lead wires in spaced relationcorresponding to the spaced relation of the hollow contacts of the base,aligning the spaced outer ends of the lead wireswith the correspondinghollow contacts of the base, and moving the base and the electricaldevice toward each other lengthwise of the set lead wires to insert thelead wires in the hollow contacts.

8. A machine for threading through a base having a plurality ofdefinitely spaced apertures a plurality of lead wires of an electricaldevice having an end member from which the lead wires project indefinite spaced relation comprising guiding means for holding the devicecoaxial with and slidable along the longitudinal axis of the guidingmeans, wire setting mechanism comprising a finger mounted to reciprocatetransverselyof the longitudinalaxis of saidguid ing means and having anundercut sideslot wider than a lead wire, actuating" mechanism formoving' the finger in one-direction to-place said slot further fromthe-axis'of the guiding means than the corresponding aperture of thebase in said holder and in the other direction to substantially alignthe end of said slot with the corresponding aperture in the base, and astop on said guiding means for-positioning at will a device in saidguiding means with the end portion of a leadwi're-in-theplane ofmovement of said finger.

9-. A machine for threadingthrough a base having a plurality ofdefinitely'spaced apertures a; plurality" of lead wires of an electricaldevice having an end member from which the lead wires project indefinite spaced relation comprising a guide for holding the device withthe lead wires projecting in the direction of the longitudinal axis ofthe guide, wire setting mechanism comprising a plurality of fingersmounted to reciprocate transversely of the longitudinal axis of saidguide, each of said fingers having means for engaging a lead wire, andactuating mechanism for moving the fingers outwardly and away from the.axis of said guide a distance greater than the spacing of the leads insaid end member and inwardly and toward each other to space the ends ofsaid slots to correspond to the spacing of the apertures in the base.

10. Means for threading the lead wires of an electrical device having anenvelope'with lead wires extending from an end member thereof into abase having spaced apertures comprising an envelope guide for slidablysupporting the envelope with the lead wires projecting lengthwise ofsaid guide, base guiding means for positioning a base in substantialalignment with an envelope in said envelope guide, fingers movabletransversely of the lead wires for engaging the lead wires and bendingthem back and forth transversely of the envelope by movement of saidfingers, and actuating means for moving said fingers to bend said leadwires outwardly and then bending them back to set them with their freeends in registry with the apertures in the base.

11. Apparatus for positioning in predetermined spaced relation aplurality of lead-in wires which project side by side from the wall ofan envelope comprising a guide for holding the envelope with itsleading-in wires extending in the same direction as the longitudinalaxis of said guide, means for engaging each wire at a point adjacent theenvelope in said guide and bending the wire away from said axis of saidguide in one direction sufiiciently to work harden the wire adjacent theenvelope, and means for pushing the outer ends of the wires in theopposite direction toward said axis of said guide to set the ends ofsaid wires in a space relation corresponding to the spaced arrangementof contact pins on a base for the envelope.

12. A machine for threading into spaced hollow contact pins a pluralityof lead-in wires projecting side by side from the wall of an envelopecomprising a guide for holding an envelope with its projecting leadwires substantially parallel to the longitudinal axis of said guide,means for bending the wires of an envelope in said guide away from saidaxis of said guide into a position at a suificient angle to said axis towork harden said wires at the bends and means for moving the outer endsof said wires back into a spaced relation corresponding to the spacedrelation of said contact pins for insertion of said wires into saidhollow contact pins. y l

13. Means for positioning lead wires of a bulb for insertion intosymmetrically spaced contacts comprising a guide for supporting a bulbwith its. lead wires projecting alongside the longitudinal axis of saidguide, wire positioning members movable back and forth transversely ofthe longitudinal axis of said guide for engaging said wires near thewall of a bulb in said guide, and actuating means for moving saidmembers back and forth to work'harden said wires by bendingsaid wiresback and forth near the wall of the bulb, and to position said wireswith their free ends in spaced relation corresponding to the spacedrelation of said contacts.

14. A machine for threading a plurality of lead-in wires of an envelopeinto hollow contact pins arranged in a circle on a base for theenvelope, comprising a way for slidabl guiding the envelope along itslongitudinal center line and parallel to the holes in the pins to bethreaded, a finger slidable perpendicularly to said line and having ahook for engaging one ofsaid wires near the envelope, actuating meansfor moving said finger with its hook engaged wire laterally away fromsaid line to outwardly bend and set the wire and for also moving saidfinger with its hook inwardly against the set of the wire to push thewire into an upstanding the endsvof the wires in a circle correspondingto the circle in which the hollow contact pins are arranged, and meansfor guiding the base to bring the hollow ends of the pins into registrywith the ends of the wires.

ANTHONY J. VASSELLI.

